Until I visited Pixar's offices, I did not know that 12-year-old boys were allowed to run major corporations. Yet I am walking through the lobby, and the room to my right is full of plastic bins dispensing every kind of cereal, free. Men pedal scooters past me. On Friday mornings an employee named Mark Andrews stands on the front lawn in a kilt, challenging co-workers to actual sword fights.

Deep in the back of the giant main building on Pixar's 22-acre campus in Emeryville, Calif., animators work inside toolsheds designed like castles, jungles and Old West jails. In one office, a...